The present invention relates generally to recording a route of a moving object. More particularly, the present invention relates to a method and system for optimizing the accuracy of the represented route to the actual route using limited resources.
It is often desirable to record the route of moving objects or craft, to include automobiles, watercraft, or aircraft. Such information can be used for fleet management, to include route optimization. In other applications, mere tracking of a vehicle's path may be desired for investigative purposes. Records of routes traveled can be desirable for safety and supervisory reasons as well. Clearly, there are a multitude of situations in which recording the route of a vehicle or a person is desirable.
Conventional tracking and waypoint acquisition methods include continuously recording global positioning system (GPS) data at a constant sampling frequency, and recording based on distance traversed. Waypoints are data which are stored to represent, recreate, a route and may be associated with a location of interest to the user. Waypoints may also be data records associated with turns, intersections, or other points of interest or route significance. Waypoints can have various position and information data associated with them, to include latitude, longitude, street name, time, and perhaps a user assigned waypoint name.
The numerous ways in which vehicle location can be sampled may impact, among other things, the recorded route accuracy. For example, the position of a vehicle could be sampled as a function of time. If the sampling interval were constant, the same number of vehicle positions, or waypoints, would be recorded in a time period of thirty minutes, regardless of whether the vehicle were standing still or cruising at highway speeds. A similar comparison is drawn to recording positions of a watercraft. A constant time interval for aircraft can also be limiting, in that, for example, position data of an aircraft while on the ground may not need to be sampled at the same interval as the position data of the aircraft when airborne.
The operation, utilization, and tracking of un-manned vehicles can also benefit from an accurate and efficient route recording system and method. In addition to vehicles, there are numerous applications for route recording of mobile instrumentation. While vehicle position may be derived solely from GPS data, instrumentation or other equipment may comprise a gyroscope for position data and a distance encoder. A system and method of route recording which is compatible with data from a GPS or from a gyroscope with a distance encoder, such as that mounted on mobile instrumentation, is desirable.
Examples of route representation in non-vehicles include recording the route of drill heads, or down-hole instruments. Accurate and efficient route recordings of such instrumentation or excavating equipment can provide valuable information for oil field management, operation, and safety at large.
Differences in use, terrain, or purpose for monitoring can make a constant rate sampling protocol yield an inefficient and inaccurate route recording. Sampling and waypoint storage, as a function of vehicle or instrument speed can be limiting as well. For example, recording vehicle position at higher speeds may not be necessary on a straight path. Conversely, recording vehicle positions less frequently under lower speed conditions may also not be desirable because of frequent changes in vehicle direction.
In some situations, there is a desire to minimize the number of points recorded to represent the route because of memory limitations, memory conservation objectives, data transfer constraints, the extensiveness of a routes, or processing burdens. In other situations, recording of minute displacements are needed to ascertain deviations from an intended route and an executed route. Comparisons of routes may be desired, which may yield yet another set of desired criteria for waypoint recording. For example, a comparison of flood routes before and after significant construction may be desired.
Waypoint recording at a constant frequency or recording which is dependent upon vehicle or instrumentation speed can yield an inaccurate represented route. Route recordings under various mobility means to include: land vehicle; aircraft; watercraft; non-motorized vehicles; persons; un-manned vehicles and non-vehicle instrumentation can all benefit from a method of optimized waypoint selection and route representation.
It is also desirable for a user to have control over the memory requirements and processing demands and the effect of the same to the accuracy of a represented route. An accurate representation of a route which optimizes the use of available memory or reduces memory requirements, while enabling efficient processing of position records into route representation is desirable. A method of assessing the accuracy of a recorded route is also desirable.